As digital communication becomes more commonplace, the need for securing the associated communication channels becomes increasingly more important. For example, current technologies allow a user to remotely access bank accounts, medical data, and other private and sensitive information.
Cryptology has been widely used to provide secure digital communication. Cryptology generally relates to the enciphering (or encrypting) and deciphering (decrypting) of messages. The encryption and decryption uses some secret information (such as a key). In different encryption methods, a single key or multiple keys may be used for encryption and decryption.
Currently, two types of ciphers are in common use. A block cipher operates on a large block of data. A stream cipher, on the other hand, operates on relatively smaller units of text (such as bits). Depending on its implementation, stream ciphers can be much faster than block ciphers.
Stream ciphers have become of special interest recently because the stream generated by them (also known as keystreams) approach the high security of one-time pad or Vemam cipher. Generally, one-time pad cipher generates a keystream with the same length as the text message being encrypted. The one-time pad keystream is believed to be completely random, yielding very high security levels, but suffers from memory overhead that may be undesirable for some applications.
Stream ciphers are usually built around a pseudo-random number generator. The cipher needs to be resistant to attacks, which rules out many efficient and statistically good generators that are suitable for simulation.
Accordingly, the current solutions fail to provide an efficient methodology for quick and secure data encryption/decryption using stream ciphers.